sending sms to mobile

Question

hello every one

i have 4 text boxes and one button first text box is enter the source mobile number ,2 text box enter the destination mobile number ,3 text box used for writing the message  .when i click the send button the message will sent to destination mobile number and then message charge is deducted from source mobile number (asp.net).

suppose take an example of  before sending the message source mobile number having 10 rs/- after sending the message source  mobile balance is 9 rs/-

(please this is my one of the top requirement) this is applicable to all newtworks